hgi.h

//
// Copyright 2019 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef PXR_IMAGING_HGI_GL_HGI_H
#define PXR_IMAGING_HGI_GL_HGI_H

#include "pxr/pxr.h"
#include "pxr/imaging/hgiGL/api.h"
#include "pxr/imaging/hgiGL/capabilities.h"
#include "pxr/imaging/hgiGL/garbageCollector.h"
#include "pxr/imaging/hgi/hgi.h"
#include "pxr/imaging/hgi/tokens.h"

#include <functional>
#include <memory>
#include <vector>

PXR_NAMESPACE_OPEN_SCOPE

class HgiGLDevice;

using HgiGLOpsFn = std::function<void(void)>;
using HgiGLOpsVector = std::vector<HgiGLOpsFn>;
using HgiGLContextArenaHandle = HgiHandle<class HgiGLContextArena>;

class HgiGL final : public Hgi
{
public:
    HGIGL_API
    HgiGL();

    HGIGL_API
    ~HgiGL() override;


    HGIGL_API
    bool IsBackendSupported() const override;

    HGIGL_API
    HgiGraphicsCmdsUniquePtr CreateGraphicsCmds(
        HgiGraphicsCmdsDesc const& desc) override;

    HGIGL_API
    HgiBlitCmdsUniquePtr CreateBlitCmds() override;

    HGIGL_API
    HgiComputeCmdsUniquePtr CreateComputeCmds(
        HgiComputeCmdsDesc const& desc) override;

    HGIGL_API
    void DestroyTexture(HgiTextureHandle* texHandle) override;

    HGIGL_API
    void DestroyTextureView(HgiTextureViewHandle* viewHandle) override;

    HGIGL_API
    HgiSamplerHandle CreateSampler(HgiSamplerDesc const & desc) override;

    HGIGL_API
    void DestroySampler(HgiSamplerHandle* smpHandle) override;

    HGIGL_API
    void DestroyBuffer(HgiBufferHandle* bufHandle) override;

    HGIGL_API
    HgiShaderFunctionHandle CreateShaderFunction(
        HgiShaderFunctionDesc const& desc) override;

    HGIGL_API
    void DestroyShaderFunction(
        HgiShaderFunctionHandle* shaderFunctionHandle) override;

    HGIGL_API
    HgiShaderProgramHandle CreateShaderProgram(
        HgiShaderProgramDesc const& desc) override;

    HGIGL_API
    void DestroyShaderProgram(
        HgiShaderProgramHandle* shaderProgramHandle) override;

    HGIGL_API
    void DestroyResourceBindings(HgiResourceBindingsHandle* resHandle) override;

    HGIGL_API
    HgiGraphicsPipelineHandle CreateGraphicsPipeline(
        HgiGraphicsPipelineDesc const& pipeDesc) override;

    HGIGL_API
    void DestroyGraphicsPipeline(
        HgiGraphicsPipelineHandle* pipeHandle) override;

    HGIGL_API
    HgiComputePipelineHandle CreateComputePipeline(
        HgiComputePipelineDesc const& pipeDesc) override;

    HGIGL_API
    void DestroyComputePipeline(HgiComputePipelineHandle* pipeHandle) override;

    HGIGL_API
    TfToken const& GetAPIName() const override;

    HGIGL_API
    HgiGLCapabilities const* GetCapabilities() const override;

    HGIGL_API
    HgiIndirectCommandEncoder* GetIndirectCommandEncoder() const override;

    HGIGL_API
    void StartFrame() override;

    HGIGL_API
    void EndFrame() override;

    HGIGL_API
    void GarbageCollect() override;

    // HgiGL specific API

    // Returns the opengl device.
    HGIGL_API
    HgiGLDevice* GetPrimaryDevice() const;

    HGIGL_API
    HgiGLContextArenaHandle CreateContextArena();

    HGIGL_API
    void DestroyContextArena(HgiGLContextArenaHandle* arenaHandle);
    
    HGIGL_API
    void SetContextArena(HgiGLContextArenaHandle const& arenaHandle);
    // -------------------------------------------------------------------------

protected:
    HGIGL_API
    HgiTextureHandle _CreateTexture(HgiTextureDesc const & desc) override;

    HGIGL_API
    HgiTextureViewHandle _CreateTextureView(
        HgiTextureViewDesc const& desc) override;

    HGIGL_API
    HgiBufferHandle _CreateBuffer(HgiBufferDesc const & desc) override;

    HGIGL_API
    HgiResourceBindingsHandle _CreateResourceBindings(
        HgiResourceBindingsDesc const& desc) override;

    HGIGL_API
    bool _SubmitCmds(HgiCmds* cmds, HgiSubmitWaitType wait) override;

private:
    HgiGL & operator=(const HgiGL&) = delete;
    HgiGL(const HgiGL&) = delete;

    template<class T>
    void _TrashObject(
        HgiHandle<T>* handle, std::vector<HgiHandle<T>>* collector) {
        collector->push_back(HgiHandle<T>(handle->Get(), /*id*/0));
        *handle = HgiHandle<T>();
    }

    HgiGLDevice* _device;
    std::unique_ptr<HgiGLCapabilities> _capabilities;
    HgiGLGarbageCollector _garbageCollector;
    int _frameDepth;
};

#define HGIGL_API_VERSION 2

PXR_NAMESPACE_CLOSE_SCOPE

#endif